The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Casting is a metal forming technique that involves pouring molten metal into a hollow cavity of a mold, where the cavity is the negative of the desired part shape. As the molten metal cools in the cavity, it solidifies and may then be separated from the mold as a solid part. The casting process may be used to form relatively complex metal parts that may not be economical to produce by other methods. In particular, many complex automotive components, such as transmission cases and motor housings, may be fabricated through a casting process.
During the casting process, air bubbles in the molten metal, defects in the mold, and/or excessive shrinkage during cooling may create pits or other surface flaws in the final part. If these flaws occur in a sufficiently thin region of a shell-like component used to contain a fluid, they may result in micro-leaks through the body of the casting. It has been found that a pore/hole as small as 8 μm may allow oil to leak out of a cast transmission case. Therefore, cast parts may be quality inspected and/or leak checked following the casting process to ensure that no micro-leaks/pores exist.
Accordingly, the leak testing process may add time to the production cycle during the production of the components and their assemblies. Typically, a leak testing machine must be set up to accommodate a particular part, and time is wasted during such a process. In an automated production line, however, speed, flexibility and reconfigurability are desirable qualities.